Fix function colors bug (tailwindlabs#2919)

Author: DylanVann

src/lib/evaluateTailwindFunctions.js

@@ -78,6 +78,7 @@ function validatePath(config, path, defaultValue) {
     !(
       typeof value === 'string' ||
       typeof value === 'number' ||
+      typeof value === 'function' ||
       value instanceof String ||
       value instanceof Number ||
       Array.isArray(value)

src/util/transformThemeValue.js

@@ -21,5 +21,9 @@ export default function transformThemeValue(themeSection) {
     return (value) => (Array.isArray(value) ? value.join(', ') : value)
   }
 
+  if (themeSection === 'colors') {
+    return (value) => (typeof value === 'function' ? value({}) : value)
+  }
+
   return (value) => value
 }